Garage Roof replacement.

[ricky101]

Hi,

Our Pent roof garage has fiber cement corrugated panels and is prone to joint leaks that need constant resealing etc.

Its been suggested we either replace or over clad with steel profile sheeting , but the angle of the roof is just 2.2 degrees.

Looking on the various roofing profile suppliers some say its ok for even flat roofs but others suggesting a steeper angle to prevent with water pooling and leaking though the fixings.

The existing 4x2 wooden purlins are on 18" centers.

Would welcome any comments as to be best options.

 

[THughes]

I would never over roof fibre cement as it makes getting a fixing far harder and makes access more difficult, plus its a bodge.

Strip it off and fit profiled steel sheeting and fix through the crowns rather than pans if you have such a low pitch to help mitigate those water pooling issues. If you do decide to drill through the pans you may consider adding some butyl sealant beneath each fixing. Although you would have to predrill holes to do this.

For such a flat roof, torch on could be considered more suitable, but this would be rather more costly than profiled sheets by the time sheeting and labour is included, plus its less DIY due to time constraints due to wet weather.

Be aware that your cement fibre sheets could contain asbestos if fitted before 2000.

 

[ricky101]

Stripping off the old roofing is the best way as you say but as its year 1982, 3" corrugated cement sheets we do not know if it contains any asbestos fibres, so thats one reason we were considering over cladding with steel sheeting.
There are no markings on the sheets so seems a proper lab test is needed ..?

Also there is the work and cost of removing/disposing those sheets and having the garage/workshop totally exposed.

Noticed someone covering an extension with what I assume is EDPM on OSB3 board so now wondering if thats a better way than steel sheets on such a shallow fall , though do wonder about its longevity/resilience with cats and birds like magpies who seems to peck hard at things ?